Have you looked at what is generated to see whether the store is being populated, or simply defined?
Using your variables:
- check _data to see if the values are making it into raw data for the store too. If so, problem data assoc.
console.log('store at load %o', store);
If it's being populated via an AJAX call, chances are it's getting its data after page render.
Which will not only open the console at this stage, it'll pause your app - thus allowing data to return from server before the following calls that render the data to the page.
If this latter scenario is the case, an easy option is to add promise code.
Promises is a coding technique which offers clean linear structure; success/error handlers; and best - the chance to have code fire when you have the data necessary, such as the response of an AJAX call.
Ext.ux.Ajax - an extension which adds AJAX Promises to your app, and also offers a run-through of what this technique is about.